Call of duty app won't work on my iPhone?

I downloaded the call of duty app so I can use the clan wars feature since I created a clan. I logged into the app using my ghosts account but it doesn't load the app, it just says log in at the top but there's nothing for me to log into, it just says log in with a picture of the ghosts mask underneath and the app won't load. I really need it to work so I can properly set up my clan and stuff. Can anyone please tell me what might be the problem and how to fix it?

The same problem happened to my clan members. It seemed to work fine for me and only one of my clan members. You can try to uninstall it then reinstall it and see if that fixes it. If they doesn't work then reset your phone maybe its the phone. Btw in case no one had joined your clan or if you have only a few people in your clan, would you like to join mines? (IF you R PSN) the clan name is 5WITCH